The Sphenopalatine Ganglion Block (hereinafter S.P.G.B.) was the first reported by Greenfield Sluder, clinical professor and director of the Department of Otolaryngology at Washington University, School of Medicine, St. Louis, Mo. This procedure was described as a non-invasive ganglion block for various chronic pain with no prolonged side effects. It required skillfully trained physicians to do this procedure in a medical environment. References dealing with this medical procedure are as follows:
(A) Reder M A, Humanson A S, Reder M. Sphenopalatine ganglion block in treatment of acute and chronic pain. In: Hendler N H, Long D M, Wise T N, eds. Diagonosis and treatment of chronic pain. Boston: John Wright, 1982: 97-108
(B) Ruskin S L. Contributions to the study of the sphenopalatine ganglion. Laryngoscope 1925; 35: 87-108
(C) Berger J J. et al., Does Topical Anesthesia of the Sphenopalatine Ganglion with Cocaine or Lidocaine Relieve Low Back Pain? Anesth Analg 1986; 65: 700-2
(D) Procacci P, Francini F, Loppi M, Maresea M. Cutaneous pain threshold changes after sympathetic block in reflex dystrophies. Pain 1975; 1: 167-75
(E) Ruskin A P. Sphenopalatine (nasal) ganglion: Remote effects including "psychosomatic" symptoms, rage reaction, pain and spasm. Arch Phys Med Rehabil 1979; 60: 353-9
(F) Kittrelle J P. et al., Cluster Headache local Anesthetic Abortive Agents. Arch Neurol-Vol 42, May 1985 496-498
(G) VanDyke C, Jatlow P. Ungerer J. Varash P, Byck R. Cocaine and lidocaine have similar psychological effects after intranasal application. Life Sci 1979; 24: 271-4
(H) Sluder G. The Anatomical and clinical relations of the sphenopalatine ganglion to the nose. NY State J. Med 1909; 90: 293-298
(I) Sluder G. The syndrome of sphenopalatine ganglion neuralgia. Am J Med Sci 1910; 111: 868-878
(J) Sluder G. Nasal Neurology, Headaches and Eye Disorders. St. Louis, CV Mosby, 1927
(K) Robert E. Ryan Jr. M.D., George W. Facer, M.D., Sphenopalatine Ganglion Neuralgia and Cluster Headache: Comparisons, Contrasts, and Treatment. Headache 17: 7-9, March 1977
The use of the term "block" or "blockade" in this disclosure means to stop the nerve impulse, or to stop the painful activity that is caused by the firing of the nerve treated, and also the correction of any adverse effect on the human body that is caused by the increased activity of the nerve center.
The sphenopalatine ganglion, located in the pterygopalatine fossa posterior to the middle turbinate, is separated from the nasal passage by a thin 1 to 5 mm layer of connective tissue and mucous membrane. Local anesthetics (such as lidocaine) topically applied to the appropriate region of the nasal passage can readily diffuse into the ganglion. The sphenopalatine ganglion has major branches to the trigeminal nerve, the facial nerve and the cartoid plexus, the latter communicating directly with the superior cervical sympathetic ganglion. The sphenopalatine ganglion has sensory, visceral motor (para sympathetic), and sympathetic functions.
The sensory root is connected with the maxillary division of the trigeminal nerve, these fibers modulate the rostral transmissions of pain information from the periphery, acting like a gate-control mechanism.
Blockade of the sphenopalatine ganglion may inhibit this baseline tonic activity and in so doing, close the gate, acting through the same mechanism as that proposed to explain the analgesia of transcutaneous nerve stimulation, but at a higher lever in the central nervous system. This connection may explain the success of sphenopalatine ganglion block in tic douloureux. Parasympathetic activity of the sphenopalatine ganglion is mediated via the superficial petrosal nerve; the branches going to the lacrimal gland may explain the excessive lacrimation associated with stimulation of the sphenopalatine ganglion.
The sympathetic root of the sphenopalatine ganglion is the great deep petrosal nerve which is essentially an extension of the cervical sympathetic chain via the cartoid plexus. Cell bodies in the ventral horn of the thoracolumbar spinal cord send fibers, either directly or via cervical ganglion synapse, some of which course through the sphenopalatine ganglion on their way to the periphery, and others of which synapse in the sphenopalatine ganglion. There are also sensory afferent cells with cell bodies in dorsal roots of the spinal cord which synapse on interneurons and ventral horn sympathetic cells reflexively. The peripheral axons of these fibers course through the sphenopalatine ganglion. Anatomically, this interposes the sphenopalatine ganglion in a sympathetic reflex arc which loops between the thoracolumbar spinal cord and the head.
This procedure appears to be beneficial in many patients with pain, in particular, that due to muscle spasm, vascospasm, neuralgia, reflex sympathetic dystrophy and chronic low back pain of multiple etiology (muscular, discogenic, arthritic, and metastatic), external cricoidynia, lower jaw toothache, glossodynia, earache in case of Eustachian tube and middle ear lesions, earache secondary to cancer of the larynx, the pain of laryngeal tuberculosis, relief of spasm of the face and upper respiratory tract, all syphilitic headache, malarial headache, cluster headache, ophthalmic migraine, dysmenorrhea, intercostal pain (neuralgia), gastric pain, nausea and diarrhea, myalgias of the neck muscles, sciatica, maxillary neuralgia, sensory facial neuralgia, pain in the upper teeth and sensation as through teeth were too long, tooth extraction or other dental procedures, feeling of foreign body in the throat, persistant itching in the external ear canal, herpes zoster oticus, taste disturbances, atypical facial pain, tic douloureux, cervical arthritis, myofascial syndrome, peripheral neuropathy, post-herpetic neuralgia, fracture secondary to osteoporosis, extremity arthritis and various arthritic conditions and lumbosacral strain. Since the pain transmission pathway for these various conditions have a similar relationship to the SPG, therefore, the impact of the SPG block should be equivalent (see discussion above). Further indication not related to pain control is the control of rage reaction and improvement of depression in the psychiatric patient. While the SPG block is effective in controlling chronic pain, it is accomplished by medical professionals by using the pledget delivery method. In the pledget method, usually two cotton-tipped applicators are inserted into one of the two nostrils of the patient (there are two SPG, one on the left, one on the right) and using the middle turbinate as an anatomical landmark guideline, the two applicators are pushed upward until they contact the desired area in a blind approach. The success rate of the procedure is directly proportional to the experience of the physician. Lidocaine is applied on the cotton of the applicators and is then applied to the SPG area via the soaked cotton. This method delivers an imprecise amount of medication to the area being treated and if in excess, can cause undesirable side effects such as throat irritation or systemic hypotension leading to shock and induce trauma to the nose. In addition, use of the pledget method could deliver less than an effective amount of medication, or miss the appropriate area to do this SPG block therefore resulting in failure of the desired results. These cotton-tipped applicators must be retained inside the patient's nose for a period of at least thirty minutes and often cause severe pain. It is necessary that the pledget method be conducted by a medical doctor who is trained as a medical specialist in the areas such as: ear, nose and throat, rehabilitation medicine or neurology in a hospital, doctor's office, clinic or other medical environments. There is therefore a pressing need for a procedure to accomplish the SPG block with applicators other than the heretofore used cotton-tipped applicators.
There are many known medical applicators as described in prior art U.S. Pat. Nos. 475,035; 2,672,141; 3,369,543; 4,402,684 and 4,405,308. In 475,035 (Van Woud) an atomizer is disclosed for dispensing medication into the nose. This type of device, however, would be ineffective in the S.P.G.B. procedure because like U.S. Pat. No. 2,672,141 (Filger) the nasal spray from the opening of the nostril will not get to the appropriate area to effect the SPG block. The anesthetic liquid from these devices most likely would drip down into the throat impairing the swallowing reflex and causing fluid to go into the lungs. It is important in the S.P.G.B. procedure that a precise quantity of medication be delivered to the treated area, a dead end area at the back of the nose measuring above 5.5 cm away from the nares. Neither Van Woud's or Filger's device is capable of this requirement. Thus, neither device is suitable for the present procedure.
In U.S. Pat. No. 3,369,543 to Ronco, a hollow casing type medical applicator is disclosed. In Ronco's device a hollow casing of an elongated deformable material with an open end is used to dispense medicine from the casing. A wick is used in the open end to provide capillary transmission of the medicine to the area to be treated. The size of casing 11 of Ronco would render it non-functional for interior nasal applications. Ronco's device is intended for treatment of external areas of the body and would not be capable of delivering a precise amount of medication to the interior of the nose to accomplish the SPG block.
In U.S. Pat. Nos. 4,402,684 (Jessup 1) and 4,405,308 (Jessup 2) anesthesia devices are disclosed using cannulas. These devices are used for trachea anesthesia and do not produce a single "shotgun-like" jetstream spray at a measured amount or volume of medication as required in the SPG block procedure for acceptable results.
Therefore, none of the above applicators could effectively be used in the S.P.G.B. procedure.